Method of purifying, concentrating, and converting petroleum sulfonates with glycols



Filed July 12, 1954 Feb. l2, 1957 u. s. BRAY METHOD OF' PURIFYING, CONCENTRATING AND CONVERTI PETROLEUM suLFoNATEs wrm GLYcoLs 4 sheets-sheet 1 Filed'July 12, 1954 Feb. 12, 1957 u. B. BRAY 2, METHOD oF PURIEYING, coNcENTRATlNG lAND coNvERTING PETROLEUM suLFoNATEs WITH GLYcoLs 4 Sheets-Sheet 2 Y M5 AVTOQNE. Hole/ws, 1050/, F0575@ a: MAW/5 FIG. 2.

Feb- 12 1957 u. B. BRAY 2,781,317

METHOD 0F PURIFYING, CONCENTRTING AND CONVERTING PETROLEUM suLFoNATEs wrm GLxcoLa Filed July 1:2,l 1954 4 Sheets-Sheet` 3 Feb 12, 1957 U.B. B AY A2,781,317'

METHOD 0E PURIFYING. CONCEN A'TING AND CONVERTING PETROLEUM sULFoNATEs WITH GLYCOLS Filed July 12, 1954 4 Sheets-Sheet 4 Us H @NNN v .N GHB..

United States Patent O Ulric B. Bray, Pasadena, Calif., assignor to Bray Oil Company, Los Angeles, Calif., 'a limited partnership Application July 12, 1954, Serial No. 442,491

17 Claims. (Cl. 252-33) This invention relates to the purication and concentration of hydrocarbon sulfonates of the oil-soluble or mahogany acid type, and to the conversion of these sulfonates to polyvalent metal sulfonates. This application is a continuation-impart of my `earlier application Serial No.' 167,798, filed June 13, 1950, issued as Patent No. 2,689,221.

In `the preparation of some rust preventing compounds and lubricants, and in the preparation of some lubricants for severe service uses and for similar lubricating uses, it has been a practice for many years to employ various metal salts of su1fonic""acids derived from the reaction of sulfuric acid and vvpetroleum fractions in the lubricating oil range. These sulfonic acids, and their salts are Well known in the petroleum industry. Those most commonly used for the present purpose are the oil-soluble acids known as mahogany acids which are found in solution in a supernatant oil layer which accumulates above an acid sludge layer upon settling of a batch of petroleum lubricating oil following strong sulfuric acid treatment. The sulfuric acid treatment of petroleum `lubricating oil results also in the production of other sulfonic acids, known as green acids, which are primarily water-soluble and are, therefore, found chiey in the acid sludge layer. However, some of these water-solublegreen acids are found in the presence of the oil-soluble mahogany acids in the oil layer and areobjectionable `for certain purposes. Possibly these vagrant water-solublel sulfonic acids pass into the oil layer 'because they are at the same time moderately oil-soluble,or because they are to that extent solubilized by the action' of the mahogany acids, or because of the failure Vto remove the last traces of pepper sludge from the acid-treated oil. As a result, these objectionable water-soluble green acids are carried `over as sulfonate into the oil-soluble sulfonate which is commonly placed upon the market as the sodium salts of the mahogany acids. For the purpose of preparing rust preventing compounds and severe service lubricants, these sodium mahogany acids salts are commonly converted by metathesis into alkaline earth metal sulfonates, usually the calcium or barium salts. The calcium salts of the true mahogany acids appear to be almost entirely insoluble in water although oil-soluble. But the resultant calcium salts of the green acids, which are readily water-soluble, are apparently also oil-soluble in 'the presence of mahogany acid salt. Because of their water-solubility, they are objectionable in rust preventives and in lubricating oils where moisture may be encountered, because they appear to weaken the resistance lto water of an oil ilm on metal, possibly through favoring the formation of a water-continuous emulsion; whereas the 4water-insoluble, oil-soluble calcium salts of the true mahogany acids, when operating in the presence of water to form emulsions, result in emulsions where oil is the continuous phase. preferentially wets 'iron or steel surfaces with the result 4that-the water present in the emulsion does not wet the In the case of oil-continuous emulsions, the oil metal and rusting is avoided. On the other hand, where the chemical environment produces water-continuous emulsions, the water phase displaces the oil from the metal surface, thereby reducing or destroying the rust inhibiting effect of the oil.` Even though the oil-soluble, water-insoluble sulfonates greatly predominate, nevertheless, appreciable proportions of water-soluble sulfonates result in undesirable effects when the polyvalentmetal sulfonates vare used as detergent additives or rust preventives in lubricants. For example, even a relatively small proportion of the water-soluble sulfonate results in excessive water corrosion, to the extent that products fail to give the full degree of protection required in severe service, such as in military and naval operation.

It is an important object of the present invention to purify alkali-metal and ammonium mahogany sulfonates by ridding them of 'the mentioned objectionable substances, to concentrate such mahogany sulfonates with respect to oil -by eliminating excess oil therefrom, and then to convert to polyvalent-metal forms the mahogany sulfonates so purified and concentrated in order that they may be useful in corresponding rust preventives and detergent lubricating oil.

Another object is to separate the green acid sulfonates and inorganic sulfates or other inorganic salts which would form insoluble salts with calcium or other polyvalent metal to be used, as water-soluble forms in a water and emulsion-breaking liquid layer from which the oil-and water-soluble, alkali-metal and ammonium mahogany sulfonates present are caused to separate.

It is also an object to provide a process for recovering oil-soluble, water-insoluble, polyvalent-metal sulfonates, such as calcium mahogany sulfonates, in oil, whereby excess oil beyond that desired in a given product is easily rejected in the presence of water and certain oil-soluble, emulsion-breaking, organic liquids, such as certain ketones, ethers and glycols. A particular object is to remove excess oil before conversion of the mahogany sulfonate to the water-insoluble, polyvalent-metal form.

It is also an object to separate the objectionable inorganic salts mentioned in a water-soluble form whereby to avoid the necessity of subsequently filtering their insoluble forms from the oil-sulfonate product, and whereby to reduce employment of lter aid and the like and the incidental costs thereof.

It is a still further object of the invention to provide a process for the recovery of petroleum sulfonates whereby formation of di'lcultly breaking emulsions, such as the large so-called cuff layers, is avoided.

Still another object of the invention is to provide a process for the treatment of crude petroleum sulfonates containing excessively large proportions of petroleum oil, appreciable amounts of water and objectionable inorganic salts and green acid sulfonates, whereby the Vobjectionable materials and excess petroleum oil are easily eliminated.

Thus, individual objects are: to eliminate all green acid `sulfonates; to eliminate all objectionable inorganic salts easily and without excessive employment of filter aid; to eliminate easily any proportion of excess oil from the sulfonates; and to provide such a process adaptable to the usual crude sodium sulfonates containing, for eX ample, up to or 85% mineral loil of various lubricating viscosities and from perhaps 0% to 50% or 60% water based on the oil-sulfonate content along with 1% to 5% of inorganic salts, approximately, such as sodium sulfate and sultite.

Ity is also an object to purify and/or concentrate crude alkali-mahogany sulfonate for use as emulsifying and wetting agents or for other desired uses to which sodium,

potassium and/or ammonium hydrocarbon sulfonates and sulfatos may be put.

It is also an object to provide a purification, concentration, and conversion process for crude sulfonates of the indicated Vcharacter whereby very large batches of crude material of high oil content and relatively low sulfonate content may be so treated with relative ease, as against treatment of only relatively small batches as heretofore.

Other objects of the invention will become apparent from the following description, as will the various features of the invention. In connection with the following specification reference is made to the accompanying drawings wherein:

Fig. 1 is a ow diagram representing the major steps of the process when operated batchwise;

Fig. 2 presents curves showing various relationships among various component materials present during the operation of the process;

Fig. 3 is a flow diagram representing the principal steps of the process when operated continuously in single or multiple stages; and

Fig. 4 is a ilow diagram representing the principal steps of the process when operated countercurrently.

Throughout this specification, the terms water-soluble and oil-soluble are used to signify either partial or complete miscibility or solubility in water and oil respectively. The term soap will sometimes be used to signify the respective sulfonate. Where reference is made to removal or elimination of green acid soaps or inorganic salts, such terminology is intended to include either complete elimination or reduction of the respective materials to such insignificant proportions that the presence of the remainder does not interfere seriously with subsequent processing or it is not detrimental for uses to which the sulfonate product is eventually to be put, where the term concentration is used, it refers to the concentration of the sulfonates with respect to the oil present unless some other meaning is obvious.

In treating crude petroleum sulfonates, various crude materials are encountered, some of which have been extracted from acid-treated oils as in the manufacture of white oils. These extracted crude sulfonates cornrnonly contain between 25% and 60% (usually about 40% or 50%) petroleum oil of various lubricating viscosities, various sulfonate contents between about 30% and about 60% soap including between about one-half per cent and 3% green acid soaps, and from 4% to 12% (for example, 8%) of sodium sulfate and sodium sulte of which the sulfate predominates. Where the crude sulfonate is a neutralized sulfonated oil, it will usually contain about 50% to 90% of oil neglecting water and salts present. The inorganic salts content of neutralized sulfonatcd oil will usually range from 0.75% to 4%.

The sulfonates are commonly salts of the alkali metal sodium and are water-soluble. They are to be purified to eliminate the green acid soaps, the sultes and sulfates mentioned, the water, and any proportion of the oil which is not desired in the iinal product and which will be ordinarily referred to herein as excess oil. The green acid soaps are to be removed because of .their deleterious effects in the end products, and the sulfates and sultes are to be removed because they interfere with the emulsifying properties of the sodium sulfonate and constitute impurities therein if permitted to remain. In addition, if these inorganic sulfates and sultes are retained, they are converted into insoluble polyvalent-metal compounds in the conversion stage and inthe case of alkali earth metals and lead settle to the bottom of the treating tank as a mud which, in the presence of the sulfonates, is coated with considerable quantities of oil because of the wetting properties of the sulfonates and presents here the problem of diflicult separation or the element of unnecessary loss of a substantial proportion of oil and sulfonate.

4 The present invention involves certain new discoveries that I have made. Thus, I have found that, at appropriate temperatures, I am able to purify crude, water-soluble, alkali-metal sulfonates before conversion to the water-insoluble, polyvalent-metal forms by commingling them with controlled proportions of water and of an emulsion-breaking, oil-soluble, at least partially Watersoluble organic liquid, the objectionable inorganic salts and green acid sulfonates passing into a water layer which settles out as a brine upon standing. Such treatment may be effected with very large gallonage and is facilitated where the water is present as a weak sodium chloride solution, for example a 5% solution.

I have also discovered that excess oil may be separated from the water-soluble.alkali-metal sulfonate by controlling the proportions of Water and emulsion-breaking liquid respective to the soap-oil content of the crude sulfonate. Generally, by holding the proportion of emulsioni-breaking liquid constant at a low levelrbetween 5 and volumes (or up to 40 to 50 volumes) per 100 volumes of soap-oil mixture (reckoned together) in the crude stock and adding water in increasing amounts, irst a brine phase appears which settles to the bottom and 3 whether or not the brine phase is` removed as soon as it appearsi but unless the brine phase is removed after appearing, it will go back into solution upon further addition of solvent and Water.

The production of both a brine layer containing undesirable inorganic salts together with green acid soaps and a rejected oil layer containing excess oil can often be accomplished in one step by careful selection of the treating doses of water and emulsion-breaking liquid, respectively. However, for greatest flexibility and ease of operation by less skilled personnel, it is usually preferred to conduct the purification and oil separation as separate steps, differing from each other mainly in the amount of water present. Reference to Fig. 2 will show for example that, with a given amount of the particular emulsion-breaking liquid within a suitable range with respect to the oil-soap content of the stock, a brine layer will appear upon increasing the water present (curves B) before a rejected oil layer will appear (curves A). However, continued increase of the water beyond a certain point causes the brine layer to decrease and eventually disappear; whereas when the critical amount of Water has been reached to cause appearance of a rejected oil phase, further additions of water cause increasing amounts of o'il to be rejected and the total amount of oil rejected tends ultimately to approach asymptotically the total amount of oil present in the stock. Likewise, at a givenl invention.

I have also discovered that after the removal of any brinelayer settling to the bottom and theseparation of the rejected oil which rises as a supernatant layer, the

alkali-metal soap inthewsoap-oil concentrate layer which contains the water and the emulsion-breaking liquid,rmay

' be easily converted to water-insoluble, oil-soluble, polyvalent-metal soap by mixing therewith a water solution of a salt ofv an appropriate polyvalent metal, the mixture being allowed to stand at appropriate temperatures for a moderate time whereupon sharp separation results between the polyvalent-metal soap and oil layer and the aqueous layer.

It is apparent that the invention comprises a complete process whereby the crude mahogany acid sulfonates are (l) purified by removing inorganic salts and green acid soaps in the form of an aqueous brine, (2) concentrated by rejecting and removing excess oil, and (3) converted to polyvalent-metal sulfonates. These three steps are eiliciently controlled by the proper adjustment of three variables; namely, variation of the proportion of water, as above indicated, employment of an appropriate proportion of emulsion-breaking liquid, and operation at a suitable temperature.

Generally temperature is not a critical variable; however, temperatures may range in the neighborhood of 140 F. to 170 F. when the various operations are conducted batchwise, and 160 F. to 200 F., when conducted in a continuous manner, `for each of the purification, concentration, and conversion steps, are conveniently employed.

Efficient proportions of emulsion-breaking liquid ordinarily range from about 5 parts to about 30 parts for each 100 parts of soap-oil (reckoned together) in the crude sulfonate to be treated.

As to water contents, while dierent stocks have somewhat different requirements, 4as is always true in any type of treatment of petroleum fractions or derivatives,

evertheless, in general, approximately 20 parts to 60 parts of water (preferably largely sodium chloride solution), are effective in the purification stage for each 100 parts of soap-oil (reckoned together) in the crude stock to remove objectionable inorganic salts, sodium sulfate and sodium sulfite, and the undesired green acid sulfonates. In the concentration stage, and/or emulsionbreaking liquid additional water is supplied if insufficient excess oil has been rejected during the purification step. Ordinarily, to 50 parts of water total per 100 parts of soap-oil (reckoned together) in the crude stock to be treated will give suitable rejection of excess oil.

Additions of either water or the emulsion-breaking organic liquid or both to a mixture whose composition is in the range for oil rejection will disturb the solvency equilibrium and cause additional rejection of oil into the supernatant layer. The resultant underlying concentrated soap layer (soap concentrated with respect to oil) may thus be made to contain oil in that proportion desired in the final product.

I have discovered that instead of using practically pure Water (city drinking water), along with the emulsionbreaking liquid, to wash out water-soluble impurities from a crude sodium sulfonate-oil mixture, I can advantageously use an aqueous salt solution in many instances. Where it is expected that purified sodium sulfonate will subsequently be converted to calcium, barium, or strontium sulfonate, it is very desirable to remove sulfates and suliites 'as far as practical to avoid formation of the waterinsoluble sulfates and sulfites of these polyvalent metals during the conversion of the soap. The presence of anions which do not give water-insoluble salts with the polyvalent metals is not objectionable from this standpoint, such anions being chlorides, nitrates, acetates, etc. Therefore, it the presence of these anions in the wash water effects greater removal of the sodium sulfate and sulfite in the brine layer during the purification step, their use is often justified. In general, chlorides of the monovalent metals are preferred, especially sodium chloride because of both its efficiency and relatively lori cost. When using sodium chloride solution in place of water during purification, the same behavior is obtained as is illustrated by the curves in Fig. 2, except that the amount of brine phase settling out for a given dosage of solvent and water, respectively, is both larger in volume and more concentrated in sulfates and sulfites.

If a purified concentrated alkali-metal sulfonate is desired as the end product, the concentrated soap layer is simply distilled to remove water and the emulsion-breaking organic liquid, and the resulting residue is recovered, with or without final purification by filtering or centrifuging while heated.

lf a purified concentrated polyvalent-metal sulfonate is desired as the end product, the concentrated soap layer is reacted with an appropriate water-soluble polyvalent-metal salt such as calcium chloride. Usually the polyvalent-metal salt is added in the form of a concentrated aqueous solution, but with proper agitation the solid salt in the form of flakes, powder, or crystals, may be added directly to the concentrated soap layer. On account of the presence of the emulsion-breaking organic liquid, the reacted mixture straties readily into a converted soap layer, containing also the remaining oil'and most of the emulsion-breaking organic liquid, and an aqueous phase containing by-product salts, excess reagent salt, and a very small proportion of emulsion-breaking organic liquid. The converted soap layer is separated and distilled or otherwise suitably treated to recover the Y emulsion-breaking organic liquid and finally dehydrated and recovered as the end product after filtering or centrifuging while heated.

While temperatures are not particularly critical, as mentioned before, nevertheless, at temperatures materially below F., viscosity conditions become a consideration because they delay phase separation, and at low temperatures such as around 100 F., the separation of the various phases may be inconveniently slow. However, if the time element is of little consequence, temperatures may be used down to 100 F., for example, without difficulty. While temperatures as high as 185 F. and up to about 200 F. produce rapid settling, they, nevertheless, may complicate the matter of maintaining adequate concentration of the emulsion-breaking liquid in batchwise operations. Therefore, a temperature of about F., or from about 140 F. to 170 F., has been found to be a desirable optimum and representative of a good compromise between speed of separation and settling of the layers and retention of cmulsionbreaking liquid in the batches during such separation and settling. Discussion of preferred temperatures in continuous operations is given below.

With respect to the emulsion-breaking liquid (which is also often herein designated as the solvent for convenience), this may be any oil-soluble, at least partially water-soluble organic liquid described below and consisting of carbon, hydrogen and oxygen, of suitably low boiling point to facilitate its removal and recovery from the various phases and of suciently low viscosity not to disturb seriously the various operations. At least partially water-soluble signifies at least about 0.01% to 10% solubility or miscibility in water. By suitable boiling point, it is intended to signify a boiling point below the decomposition point of the sulfonates so 'that the diluent liquid may be eliminated from the product by vaporization. In general, this signies a boiling point not materially in excess of 400 F., inasmuch as the initial decomposition temperature of a sulfonate, such as calcium sulfonate, may be in the neighborhood of 450 F. to 500 F. However, higher boiling solvents can be recovered by distillation under vacuum.

This class of emulsion-breaking solvents or liquids (which are often designated herein merely as solvents for convenience) is at present best represented by any of the liquid glycols (di-hydroxy alcohols), and their liquid polyglycols, which contain at least three carbon atoms per molecule, and vpreferably those having three to six carbon atoms per molecule. The liquid polyglycols of this class thus contain multiples of such three to six carbon atoms per molecule. Specific examples which have been employed successfully from the one group are:

Propylene glycol, OHCHzCI-IOHCHa Diethylene glycol, OHC2H4OC2H4OH Dipropylene glycol, OHCsHeOCsHsOI-I Hexylene glycol, OHCsHizOH Butylene glycol, OHCrHsOH In practice, dipropylene glycol is generally a preferred glycol for this process.

This class additionally contains the group of the indicated polyglycols of the members of the above group and having multiples of the mentioned three to six carbon atoms per molecule, thus:

Polypropylene glycols having for example a molecular weight of about 750, polydiethylene glycols, polydipropylene glycols, polyhexylene glycols, and polybutylenc glycols.

A representative formula of the polyglycols is the polypropylene glycol thus:

Having reference to the accompanying batch flow diagram of Fig. 1 and also to a particular crude alkalimetal sulfonate which is a neutralized sulfonated oil as an example of various crude sulfonates which have been successfully treated, a preferred method of procedure, which embodies the various aspects of this invention is set out below.

The foregoing crude alkali-metal (sodium) sulfonate contains about 7.5% water, 16% total sulfonates, 74.5% oil, and 3% inorganic salts. The inorganic salts are principally sodium sulfate with a very minor proportion of sodium suliite, both of which are to be removed by this method. The total sulfonate content consists of 14.5% mahogany acid soap and 1.5% green acid soap. It is desired to remove the green acid soap without loss of mahogany acid soap. It is desired also to remove excess oil and produce a concentrated calcium sulfonate containing 40% soap. It is further desired to convert any trace of sodium sulfonate appearing in the removal oil to calcium sulfonate in order that the removed oil may be used in formulating engine oils, rust preventive oils, etc.

Puriycntion stage-To the particular starting material, above described, water is added in an amount equal to approximately 20% of the crude stock, corresponding to 21.5% based on the oil-soap content `of the crude stock. Preferably a 5% sodium chloride solution is employed because the sodium chloride serves efliciently to displace the sodium sulfate and the sodium sulte so that the latter salts will come out in a settled brine layer. The less sodium chloride used, the less efficiently are the sultes and sulfatos eliminated. While stronger concentrations of sodium chloride may be employed, or for example, to obtain greater removal of sulfates and sulfites, the additional cost is usually not considered justified. This is particularly because the amounts of sulfatos and sultites which are not removed by employment of a 5% sodium chloride solution in the proper dosage are insutiicient to detract seriously from the usefulness of the purified sodium sulfonate as such or as a raw material for making polyvalent-metal sulfonate.

To the crude sulfonate stock there is also added, between about parts and about 30 parts per 100 parts of stock of the selected emulsion-breaking organic liquid or solvent described, such as dipropylene glycol, based on the crude stock. ln using dipropylene glycol or other indicated glycol, the glycol may contain water, in which case appropriate allowance is made for such water content of the glycol in formulating the treatment of a batch of stock.

In a particular instance, 100 gallons of the described crude sodium sulfonate stock containing about 16% total soap and about 7.5% water were pumped into a treating tank in admixture with 20 gallons of Water and 20 gallons of the mentioned glycol as the emulsion-breaking liquid or solvent. As is represented in the batch flow diagram of Fig. 1, the sodium chloride solution and the solvent are introduced by pumps into the crude sulfonate steam on its way to a heater 10 in which the mixture is heated to about 150 F. to 170 F. and from which it is passed into a tank 12. When the entire batch is charged, it is agitated for 20 to 50 minutes to insure equilibrim between all components.

The heated and agitated mixture in tank 12 is then allowed to stand and settle for several hours, for example over night, or other appropriate period of time which may range from four or five hours up to any other desired time. During this interval the temperature gradually drops with this volume of material to about F., the temperature, however, being at all times adequately high to assure good separation of a water (brine) phase which settles out in the bottom of the tank, as indicated, and carries with it all objectionable proportions of green acid soaps, sodium sulte and sodium sulfate, and similar objectionable inorganic salts. Not only do the sulfites and sulfatos separate in the lower brine layer, but the green acid sulfonates are also carried down in this brine layer because apparently they are preferentially soluble in the water of the brine layer, whereas the mahogany acid sulfonates which remain in the supernatant layer are preferentially soluble in the oil and in the oil-soluble solvent.

After sufficient standing and settling, the separated brine layer is withdrawn from the bottom of the tank. In the particular example above given, the brine layer measured 30 gallons at about 140 F., and the soap-solvent layer measured 38 gallons, there being 72 gallons 4of oil which was rejected. Preferably the Withdrawn brine is passed to a vacuum still and the dissolved solvent driven off and recovered.

Concentration stage-lf further concentration is desired, the above described soap layer containing the oil, solvent, and mahogany soap is passed from the tank 12 through a heater 14 and upon its way to the heater is mixed with a quantity of tap water and/or solvent sufficient to unbalance the previous solvent relationship between the oil, soap, and solvent so that upon further standing and settling any desired proportion of the xecess oil in the soap-oil-solvent layer is rejected depending on the amount of water and/or solvent added. In the specitic instance water equal to 20% of the original charge of crude stock was introduced. In the heater 14 the soap-oil-solvent mixture with the added water is raised to a temperature of about F. to 170 F., as before, and this mixture is then either returned to the tank 12 or passed to another tank 15 as indicated in the flow diagram, where it .is agitated to insure equilibrim being established again.

In the tank 15, the heated mixture is again allowed to stand and settle over night, or for several hours, so that the oil rejected by reason of the change in the solvent relationship separates as a supernatant layer above a soapoil concentrate containing the solvent and the water. In the example described above, where the crude stock contained 74.5% oil, approximately 90% of the oil in the crude stock was rejected into the supernatant layer, while 10% of the oil in the charge remained in the underlying soap layer. In effect, oil appears to be rejected under a given set of conditions until the ratio of soap to oil in the soap containing phase satisfies the equilibrim requirements for that set of conditions (apparently without regard to the quantity of oil in the original charge of stock). Obviously, if the proportion of oil to soap is already below the equilibrim requirements, no oil will be rejected under that particular set of conditions. As more water and solvent are added, however, a point will be reached where oil will be rejected. We have thus been able to concentrate alkali su'lfonate to a degree where 9 only 22 parts of oil remained for fonate.

Conversion stage-The aqteous soap concentrate (containing the solvent and some oil) which settles out in the tank 15 is next subjected `to treatment to convert the alkali-metal, water-soluble, oit-soluble, mahogany sulfonate into a water-insoluble, oil-soluble, polyvalent-metal Vsulfonate. This is accomplished by passing the settled layer of the soap-oil concentrate from the bottom of the tank 15 to a heater 16 to restore its temperature, and by cornmingling this concentrate with a water solution of an appropriate polyvalent-metal salt. Commonly, calcium sulfonates are produced, and for this purpose a to 40% solution of calcium chloride in water is used, this solution being commngled with the soap-oil concentrate as it is passed to the heater 16 whereby to raise the temperature of both thecalcium chloride solution and the concentrate to about 150 F. If the rejected oil has been removed from the tank (or tank 12) to some other tank, such as tank 13, the mixture heated in the heater lo may be returned tothe tank 15 (or the tank 12) or it may be passed to a, conversion tank 20. As before, the heated mixture is allowed to stand and settle for several hours, or over night, whereby a water solution containing excess calcium chloride and sodium chloride settles out to leave a clear, supernatant layer of calcium sulfonate concentrate in oil together with the bulk of the solvent and a limited amount of `entrained or dissolved water.

In operating with the original 100 gallons of crude sulfonate of the above example, the amount of calcium chloride used to convert the mahogany sulfonate in the concentrate was about 30 pounds which was dissolved in about eight gallons of water. Y

In order to provide a consistent control of the concentration of the sulfonate in the end product, it has been found both easy and desirable to reject more oil than necessary during the rejection operation and then add back an appropriate amount of the same or another more desirable oil at a later stage to regulate the soap concentration in the nal product. Where the concentrated sodium snlfonate is to be converted to a polyvalent metal sulf-onate, the concentration adjusting oil may be added before, during, or after the conversion to the polyvalentmetal sulfonate. In the above example, a portion of the rejected oil phase was pumped into the conversion tank 1S foilowing the transfer of the concentrated sodium sulfonate phase to the conversion tank 20.

Normally, in the conversion stagerit might be expected each 7s para of sur that, in view of past experiences, the calcium or other polyvalent-metal sulfonate formed in such concentrated oil solution would result in the production of a very refractory water-in-oil emulsion. However, in conjunction with the described emulsion-breaking organic-liquid solvent the phases break readily and separate sharply in the tank Within a few hours to yieldran underlying brine layer of sodium chloride `and calcium chloride in water with a sharply deiined supernatant layer of polyvalentmetal soap in concentrated condition in the oil present, together with the bulk of the emulsion-breaking liquid used and a proportion of water which is readily removable during a subsequent dehydration step. lI have no` particular theory regarding the action of the indicated class of organic compound. Apparently the function of the emulsion-breaking liquid, is not so much that of a selective solvent as that of breaking up an otherwise stable oil-continuous emulsion, or, possibly that of preventing formation of such an emulsion.

The calcium soap-oil-solvent layer is then passed to a still 22. to distill olf the solvent, which is recovered and sent to storage, and to dehydrate the oil-soap concentrate to yield a finished product which may be placed in storage, as in a receptacle 24, either with or without iiltering or other further treatment. Y

Inasmuch yas the excess oil rejected in :the concentration stage in tank 1S may con-tain a very small arnount'of mahogany soap, 'this soap should be converted into calcium or other polyvalent-metal soap. Therefore, such oil, having been passed for example to the tank 18 for treatment, is recirculated through a heater 25 in admixture with the excess calcium chloride in the water solution drawn from the conversion tank 20, and the temperature again brought up to about 150 F. to 170 F. The heated mixture is allowed to stand in the tank 18 until the Water solution separates in the bottom and leaves a supernatant oil layer containing the small amount of resultant calcium sulfonate. Such oil, which is commonly of lubricating viscosity, is useful in lubricating, rust-preventing, and other petroleum compositions and is therefore dehydrated and recovered as a valuable product. j

By finishing the converted soap layer and the converted rejected oil layer separately by adding Ca(OH)2 (calcium hydroxide) to insure alkaline products, distilling to recover solvent and remove water, finally heating to approximately 300 F., and then filtering with the aid of a small amount of diatomaceous earth, a yield of alkaline calcium sulfonate concentrate having a sulfated ash value of 7% to 8% may be obtained,la.nd`a yield of by-product (rejected) oil having a sulfated ash value of about 0.01% to 0.10% may be obtained.

Referring to various aspects of the above-'described treatment, in the purification step the dosages of Water (or NaCl solution) and emulsion-breaking liquid are best selected with respect to each other. It is apparent from Fig. 2,that, for each solvent dosage in the range of 51% to 15% based on the Voil-soapcontent of the stock, there is an appropriate range of water content of the mix (the sum of both the water present in the stockand the Water added) for any given solvent content. This appropriate Water content of the mix will usually be found in the range of 10% to 60% water based on the oil-soap content of the stock. Furthermore, in the appropriate Water range for any given solvent dosage, there will be a somewhat narrower preferred range of water content, as is to be expected from the fact that with water contents, below and above the appropriate range, no brine phase is produced. For example, a dipropylene glycol dosage of 20 parts and a total water content of 17.5 parts (10 parts added and 7.5 parts in thejstock) per 100 parts of stock gave about the same extraction of salts and other impurities (such as green acid soap) as dipropylene glycol dosage of 2O parts and a total water content of 27.5 parts. In the first case the yield of brine was 24 parts as compared with 30 parts in the second, but the brine in the first case was more concentrated. (Other crude sulfonates will have somewhat different optimum ranges but the appropriate range will be found within the general order of magnitude indicated for the stock shown above.) While the-extraction of impurities was about the same in the two cases, the purified soap layer amounted to 36 parts in the rst case and 38 parts in the second case, the amount of rejected oil being 70 and 72 parts, by volume, respectively. Sometimes it is preferable to avoid simultaneous rejection of oil along with the brine, as for example in one method of operating a continuousextraction column, but in the batch method, simultaneous separation of oil is of little consequence, and the dosages of solvent and Water are chosen to give the optimum extraction of salts and other water-soluble impurities regardless of simultaneous rejection of oil from the soap phase.

In the event suiiicient oil is rejected under conditions of optimum extraction of water soluble impurities, then subsequent rejection of oil is obviously unnecessary and the concentration step is therefore completed along with the purification. On the other hand,`if the purification conditions chosen do not reject the desired proportion of oil, then the brine phase is removed and additional water is then added to bring up the total water used (including water originally in the stock) tothe place on the curve where the desired amount of oil is rejected. Instead of adding water, more solvent, or' both solvent and water, may be added to cause additional rejection of oil. If the purification and concentration are to be conducted separately, the brine settled in the purification step should be removed before any appreciable additional water or solvent is added, lest the brine redissolve in the mix. Good solvent contents are found in the range of 10% to 50% of the total water content, or within a range of about to 50% based on the oil-sulfonate content. The economically and operatively preferred range, if not the most efficient range, is from to 40% of the solvent or emulsion-breaking liquid, based on the oil-sulfonate content.

In the event the crude sulfonate as received contains too much water to give a brine phase upon the addition of the specified solvent, the excess water is removed by evaporation substantially in toto or, if desired, until the amount remaining corresponds to the working range for the usual solvent dosage of 10% to 35%. The evaporation may be by distillation or by heating and air blowing. In general the most satisfactory procedure is to remove most of the water and then add back the desired amount as the stock is processed in accordance with Vthis invention.

In purifying crude sulfonates containing a high ratio of soap to oil, it has been found convenient and efficient to adda substantial amount of lubricating oil to the stock or to the mix being treated for the two-fold purpose of reducing the viscosity and reducing the solvent power of the soap phase for water-soluble impurities. As long as the oil added is of suitable quality, this entails little or no hardship because this amount of oil is easily rejected, after the removal of the brine layer, by addition of water or solvent and thereby recovered. In this instance the rejected oil may be recycled without removal of dissolved or entrained solvent and water.

In the foregoing example of a commercial operation of the process, the method of treatment is batchwise for each of the purification, concentration, and conversion steps. In many instances, however, particularly where the demand for the finished sulfonate is steady and of suicient magnitude, it is desirable to operate the process in a continuous manner.

Figure 3 illustrates continuous operation of the process with single stage treatment by the reactants. Fig. 4 illustrates continuous operation of the process with countercurrent flow of reactants. Many modifications and combinations of the steps will be readily apparent to those skilled in the art from the disclosures contained herein. For example, multiple treatments may be given at each step of the process of Fig. 3, when necessary to obtain complete results.

Referring to Fig. 3, the crude sulfonate in a storage tank 31 is fed by a pump 32 at a controlled rate through a line 33 to the processing system. The emulsion-breaking liquid solvent specified herein is charged at a controlled rate through a pump 34 into the line 33 through which the crude sulfonate is flowing. Water or aqueous sodium chloride solution is charged through a pump 35 at a controlled rate also into the line 33 through which the crude sulfonate and solvent are flowing. The mixture of crude sulfonate, solvent and water flows into a mixer 36 which is equipped with suitable agitators and baffles to insure chemical equilibrium of the reactants and reaction products as they emerge from the top of the mixer 36 through a line 37 and flow into a settling vessel or purifier 38. In this vessel, the soda brine phase containing sodium sulfte, sodium sulfate and other water-soluble impurities such as green acid soap, settles to the bottom and the purified sulfonate rises to the top. The settled soda brine is withdrawn through a valve 39 actuated as by a suitable liquidv The purified sulfonate practically free of brine droplets overflows from`-the tank 38 to a line 40 through which it is forced by a pump 41 into a mixer 42. Water is charged by a pump 43 into the line 40 through which the purified sodium sulfonate is flowing. Mixer 42 is equipped with suitable agitators and baffies to insure equilibrium between the reactants and reaction products by the time they emerge through an upper line 44 and flow into a settling vessel o-r oil rejector 45. The mixture entering the vessel 4S stratifies into a concentrated soap and oil layer settling to the bottom and a rejected oil iayer rising to the top and removed through an upper line 45a. The concentrated soap layer is transferred from the bottom of the vessel 45 through a lower line 46 by a pump 47 and a valve 4S which are controlled by a suitable liquid level device in the settling vessel 45. A relatively concentrated calcium chloride solution is charged by a pump 49 into the line 46 through which the concentrated sodium sulfonate is flowing, this stream passing to a converter or mixer 50 equipped with suitable agitators and baffles to insure thorough equilibrium between the reactants and reaction products when the mixture emerges at the top through a line 51 by which it is carried into converted yconcentrate settling vessel 52. The mixture entering the settling vessel 52 stratifies into two layers; namely, (1) an aqueous phase containing sodium chloride formed by metathesis from the calcium chloride, excess calcium chloride, and other water-soluble impurities such as the last portions of green acid soaps, and (2) an oily phase consisting of oil, converted sulfonate, and the major portion of the solvent carried through the process to this point.

The oily phase rises to the top of the settling vessel 52 and overflows through a line 53 from which it is charged by pump 53a to a solvent recovery still 54. A slurry of calcium hydroxide in either oil, water, or calcium chloride solution is prepared in an agitator 55 and pumped via a line 55a and a pump 56 into the line 53 carrying the converted soap layer to the solvent recovery still 54. In practice the still 54 is duplicated, one still being used for distillation while the other is being charged, or the converted soap layer supplied by the line 53 is accumulated in an intermediate storage tank (not shown) While a batch is being run down in the still 54, or the still 54 may be of the continuous type consisting of a tubular heater and fractionating tower. Either steam or vacuum or both may be used in the still to aid removal of the last traces of solvent and water from the converted soap layer. The converted soap layer is finally heated to a temperature in the neighborhood of 300 F. and then filtered in a filter press 57 and sent to storage 58. To aid filtration of the dehydrated calcium soap concentrate, a small amount of diatomaceous earth (e. g. SuperceL I-Iyflo), such as 1% to 2% by weight, is added before filtration. The solvent from the converted soap layer is recovered in apparatus 59 for reuse in the process.

Inasmuch as the process depends upon the presence of water in the various steps, it is usually unnecessary to remove the dissolved water from the solvent recovered from any step in the process. The water from the condenser of the solvent recovery system is occasionally fractionated to concentrate the solvent.

Since the rejected oil layer rising in the settling and oil rejecting vessel 45 contains a small amount of sodium mahogany soap which should be converted, such oil is passed by the line 45a from the vessel 45 to a mixer 60 equipped with suitable agitators and bafiies to insu-re equilibrium between reactants and reaction products. Since the bottom aqueous layer in the settling vessel 52, resulting from the reaction of the concentrated soda soap with calcium chloride solution, contains excess calcium chloride, this brine layer also is pumped to the mixer 6i) for the purpose of reaction with the soda soap in the rejected oil. This transfer is made by way of a line 61, a valve 61a, and a pump 61b controlledby a suitable liquid level device (not shown) in the vessel 52. The brine from the line 61 is delivered to the line 45a through whichthe rejected oil is being forcedto the mixer 60 by a pump 60a. Following reaction between calcium chloride and the sulfonate of the rejected oil in the mixer 60, the reacted materials leave the mixer 60 'by a line 62 and flow into a settling vessel 63 where stratification occurs to yield a calcium brine layer on the bottom and a converted oil layer on top. The converted oil layer is delivered by a line 64 and a pump 64a to a still 65 for recovery of contained solvent and dehydration of the oil. The `calcium brine layer is withdrawn from the bottom of the vessel 63 through suitable level control valves and pumps (not shown) and is processed for recovery of dissolved solvent and then discarded. A small portion of this brine can be used in the agitator 55, if desired, in making a calcium hydroxide slurry to be added either to the concentrated soap layer being charged to the still 54 or to the converted, rejected oil layer charged to the still 65. The converted by-product oil layer, in which any trace of soap ycarried over from the concentration of the soda soap in the settling and rejecting vessel 45 has now been converted in the Vessel 63 to calcium soap, when being processed in the still 65 may contain a slurry of calcium hydroxide suspended in oil or water or brine containing calcium chloride added from the agitator 55, as above indicated, or from an agitator 66 by a pump 67 via a line 68, to the charge going into the still 65. In this still, both dissolved solvent and water are removed by heating to a temperature in the neighborhood of 300 F. with the use of vacuum or steam. The liberated solvent is recovered in appropriate apparatus 69 for reuse in the process. The dehydrated solvent-free oil is filtered and sent to storage 70 for use in blending lubricating oils, rust preventives, and the like, or it may be further relined to produce white oils.

In the operation illustrated in Fig. 3, the temperature is preferably higher than in the batch method illustrated in Fig. 1, to insure etlcient operation of the continuous settling vessels; namely, in the neighborhood of 160 F. to 200 F. as previously indicated. VAppropriate heaters (not shown) are employed in much the same way as shown in Fig. l.

Figure 4 illustrates a countercurrent, continuous operation of the process, the crude sulfonate in storage tank 71 being fed by a pump 72 at a controlled rate through a line 73 to the processing system. The emulsion-breaking liquid solvent specified herein is charged at -a controlled rate by a pump 74 into the line 73 through which the crude sulfonate is iiowing. The mixture of stock and solvent enters the lower portion of a countercurrent extraction column 75 while water or aqueous sodium chloride is charged at a controlled rate by a pump 76 and a line 77 into the upper portion of the extraction column 75. As the mixture of stock and solvent works its way up the column, the water or sodium chloride solution works its way downward and `extracts from the stock the water soluble impurities such as sodium sulfate, sodium sulte and the green acid soaps. The brine thus formed settles in the bottom of the column 75 and is withdrawn through a valve 78 which is actuated by a suitable level control in the column 75 and is sent to a still for recovery of the solvent dissolved therein. The extracted or purified stock containing the bulk of the solvent introduced into the streamof stock in the line 73, passes out of the top of the column 75 through a line 79 and is forced by a pump 80 through a line 81 either directly into an oil rejection or extraction column 82 or via an agitator 83 by proper manipulation of valves 84, 85, and 86. Water is charged into the systemat a -controlled rate by a pump 88 through a line 89 by opening a valve 90, and/ or water is charged at a controlled rate into the top section of the column 82 by a pump `91 Via a valve 92 and aline 93. Water charged through theline 89 mixes with the puriied stock and solvent in the line 81. This mixture may be thoroughly agitated -by closing the valve 84V and opening the valves 85 and 86 and forcing the mixture through the agitator 83 which provides sufficient agitation to insure equilibrium between the reactants and the reaction products; this .usually being preferred when water is introduced by the pump 88 and line VY89 into the stream being processed. Sometimes it is desirable to introduce all of the water via the pump 91 and line .93 into the top section of the column 82, in which case the stock A{iowing in the-line 81 is made to by-pass the agitator 83 by opening the valve 84 and closing the valves 85 and 86. The water introduced into the top section of the extraction column 82 via line 93 washes countercurrently the rejected oil which is rising upward in the column 82,l and also causes rejection of oil from the purified stock in the lower section of the column 82.

In other words, partial or fairly complete rejection of oil may be accomplished by the water introduced along with the stock via the line 81 and agitator 83, while any water introduced into the upper section of the column 82 via the line 93 serves to wash out soap dissolved orentrained in the rejected oil rising from the bottom of the column.

The soda soap solution now concentrated with respect to oil settles to the bottom of the column 82 and is removed via a valve 94 anda pump 95 which are actuated by a suitable level control device (not shown) in the lowest section of the column 82. The concentrated soda soap solution is forced by the pump 95 Via a line 96 into the bottom section of a conversion or extraction column 97, going through an Vagitator 98 or by-passing this agitator by proper operation of valves 99, 100, and 101. Aqueous calcium chloride solution of-suitable concentration is charged into the column 97 by a pump 102 via a line 103 into the top section of the extraction column 97, or by a pump 104 into the bottom section of the column 97 in admixture with the concentrated soap `stock moving in the line 96. If calcium chloride solution is introduced into the line 96, it is Idesirable `to agitate the resulting mixture thoroughly before it reaches the column 97 by sending it through the agitator 98 by opening the valves 100 and 101 and closing the valve 99. If a portion of the calcium chloride solution is premixed with the stock in the agitator 9S and introduced into the bottom section of thevcolumn 97, via the line 96 along with the stock, any additional calcium chloride solution introduced by the pump 102 moves countercurrent to the reacted oily soap phase rising in the column 97 and serves to complete the conversion of sodium soap to calcium soap. The converted soap phase ilows out the .top of column 97 via a line 105 and a pump 106 and is `sent to intermediate storage tank 107 whence it is sent toa still 108, for recovery of solvent in apparatus 109, and dehydration before filtering. Lime or other reagents may be vadded to the stock in the tank 107 before it is charged Vto the still 108 by a pump 110. Diatomaceous earth vwhich serves as a filter aid is added before, during or after the distillation and dehydration. The Vdehydrated concentrate is passed through a filter 111 and the nished calcium sulfonate concentrate is sent to storage 112.

The spent or partially spent calcium chloride brine resulting from the conversion of the soda soap to calcium soap in the agitator 98 and conversion or extraction column 97, settles to the bottom of the column 97, whence it is withdrawn through a valve 113 and a pump 114 and sent to a still for recovery of dissolved solvent.

The oil rejected in the rejection column 82 rises upward and settles practically free of entrained water Vand soap in the top of the column. However it contains a very small proportion of dissolved mahogany soap which should be converted. Therefore, the rejected oil is passed from the top of the column 82 via a line 115 Vand a pump 116 into a treating column 118, and calcium chloride solution, which may conveniently be the partially spent brine layer settling to the bottom of extraction column 97, also is introduced into the top of column 113 via apump 119 and a line 120, or 4into thebottom ofthe 15 column 118 via a pump 121 and a line 122. Any calcium chloride solution introduced via pump 119 is best mixed with therejected oil phase ilowing in the line 115 by passing the mixture through an agitator 123 before it goes into the treating column 118. The operation of the conversion of the small amount of soda soap carried over in the by-product oil owing from the top of the rejection column 82 is similar to the conversion of the concentrated soda soap phase settling to the bottom of the column 82 and converted and separated in the column 97.

The converted, rejected oil in the column 118 rises to the top and is sent via a pump 124 and a line 12411 to intermediate storage 125, whence it is charged by a pump 126 to a still 128 for solvent recovery in apparatus 129 and for dehydration before filtering. After passing through a filter, this converted, rejected oil is lsent to storage for use as a lubricant, or in compounding rust preventivos or lubricants, or the like. The brine phase in the column 118 settles to the bottom and is withdrawn via a valve 131 and a pump 132 which are controlled by a suitable liquid level device (not shown) in the lowest portion of the column 118. This brine is distilled for solvent -recovery and is nally discarded.

It .is to be understood that this process, whether batch or continuous, is also applicable to the treatment of alkalimetal or ammonium sulfonate-oil concentrates of commerce which contain around 30% to 60% sulfonates and 40% to 70% oil with impurities in the form of green acid soaps, sulfates, sultes, and `the like, although this process is particularly adapted to the treatment of sulfonated oils containing the indicated lower soap contents.

It is also to be understood that where a ,reference to alkali-metal sulfonates is made in this specification and the claims lthe expression lis to be construed as including `also the equivalent ammonium sulfonates.

Additional data involving the treatment of crude sulfonate-oil stock with various solvents of the present class in various amounts is presented in the following table:

Glycol treatment-100 volumes of stock separations, vols. Glycol Vols. Water,

Vols.

Brine Soap Oil Propylene glycol 20 20 8 70 62 D 20 40 l0 96 54 Do 40 40 30 86 64 Dlethylene glycoL l0 20 8 80 42 Do 20 20 10 72 58 Do 20 40 21 102 37 Do 40 40 29 87 64 D0 40 80 54 112 54 Dipropylene g co 20 10 24 36 70 Do 20 20 30 38 72 Do-- 40 20 64 26 70 D0 20 40 20 70 70 Do 40 40 80 26 74 D0 40 80 3S 110 72 Hexylenc glycol 40 40 16 92 72 Butylene glyccL 40 40 40 77 65 Polypropylene glycol (mol.

wt. 750) 40 40 32 1 82 72 D0 l0 40 30 1 48 72 1 2 layers.

While the purified polyvalent metal petroleum sulfonates or mahogany soaps obtained in accordance with this invention are usually `calcium products, the invention, nevertheless -extends to the preparation of other alkaline earth metal sulfonates, especially barium and strontium salts. These may be prepared with watersoluble salts of barium and strontium as readily as the calcium product is produced. The process is also applicable 1to the production of other water-insoluble, oilsoluble sulfonates, and these may include the mahogany acid salts of aluminum, zinc, magnesium, lead, cobalt, nickel, and the like.

Concentra-tes of the above nature may be put to various uses. For example, the addition of 5% to 20% of the above concentrate to calcium, aluminum, barium, mag- 16 Y nesium, zinc, and lithium base greases, respectively, has both imparted markedly improved anti-rusting properties and reduced tendencies to bleeding or separation of the oil content of the greases on standing.

Rust preventives constitute another important phase of use ofthe present product. These are obtained by diluting the appropriate polyvalent-metal sulfonate concentrate with appropriate carriers, such as any mineral oil lubricating fraction suitable for the ultimate use of the product. Commonly, suc-h dilution will yield a sulfonate content between about .05% and about 6% in the blended product. Ordinarily a satisfactory working proportion is about 3% `of sulfonate, or within a yrange of about 2% to about 4%. y

Another important use of the purified, polyvalent-metal sulfonate of this invention is in connection with the production of lubricating o-ils for severe service, internal combustion engines, such as aircraft and other heavy-duty engines, including diesel engines. Here the sulfonate may be present in proportion to impart rust-preventive characteristics or for other purposes, including promotion of detergent and wear-reducing characteristics. For these purposes, typical lubricating oils may contain from about 0.5% to as much as 10%, for example 3%, of the puriiied alkaline earth metal sulfonates of this invention, together with such other additive constituents as may be deemed desirable. Depending upon the ends sought, such other materials may include sulfurized alcohols, sulfurized hydrocarbons, thiophosphates, zinc dithiophosphates, phenolic thioethers, phosphites, metal derivatives of these materials, various oil-soluble detergent soaps, such as the calcium soaps, and similar metal soaps of synthetic carboxylic acids obtained from the oxidation of paratiinic hydrocarbons, alkyl phenols, pour point depressors, antioxidants, viscosity index improvers, and kindred materials known in the lubricating industry.

I have found that it may be desirable, as, for example, for detergent purposes and anti-corrosion purposes, to leave in the finished product a small proportion of the glycol, for example, one-tenth percent to two percent based on the weight of the soap. With some of the higher molecular weight glycols, such small proportions -may be used that all the glycol may be retained in the product. I have also found that the presen-ce of 0.25% to 2% of -octyl alcohol or other high molecular weight alcohol in the nished lubricant increases very greatly the effectiveness of the sulfonate addition in combating corrosion from hydrobromic acid. For example, the addition of 2.5% calcium sulfonate to a heavy-duty motor oil containing 0.75% calcium soap of oxidized petroleum aci-ds and 0.75% calcium salt of :tertiary amyl phenol sulfide 'was sufficient to protect the crankcase interior yof engines against rusting from moisture condensation, but was insuilcient to protect against dilute aqueous hydrobromic acid. The addition of 0.75% of octyl alcohol (2-ethylhexanol) to the foregoing oil containing 2.5% sulfonate, as described, gave perfectprotection against hydrobromic acid corrosion.

While I have described the process as being applicable to petroleum sulfonates produced by sulfuric acid treatment of petroleum fractions particularly those in the lubricating oil range, the process is also applicable to sulfonates produced synthetically by sulfonation of hydrocarbons or other compounds from coal tar products or any other source. Also, the process is applicable to sulfates (often called sulfonates) produced by reacting sulfuric acid or sulfur t-rioxide with alcohols and/ or unsaturated compounds belonging to the classes of hydrocarbons, acids, ester, ketones, ethers, glycerides, waxes, etc.

inasmuch as variations of the different features of the generic invention herein disclosed will do doubt occur to those lskilled in this particular art, it is intended to cover all modifications which fall within the scope of the patent claims.

I claim as my invention:

l. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and Water-soluble inorganic sulfate and sulte, which comprises: forming ya mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said water-soluble inorganic sulfateand sulte, at least 10 parts by volume of Water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least parts by volume per 100 parts by volume of said hydrdocarbon oil and sulfonates of -a hydrocarbon oil-soluble emulsionbreaking liquid which is a glycol containing three to six carbon atoms per molecule, the amounts of said water and said emulsion-breaking liquid being sulicient to produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon oil, water and emulsion-breaking liquid, a hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase and an aqueous phase containing alkali metal green acid sulfonates and water-soluble inorganic sulfate and suliite; and separating said three phases from each other.

2. The process as defined in claim 1 in which the temperature of said hydrocarbon oil phase and said concentrated sulfonate phase during said separating is between 140 F. and 200 F.

3. The process as defined in claim 1 in which the emulsion-breaking liquid is dipropylene glycol.

4. The process as defined in claim 1 in which the emulsion-breaking liquid is propylene glycol.

5. The process as defined in claim l in which the emulsion-breaking liquid is diethylene glycol.

6. The process as dened in claim 1 in which `a watersoluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali metal'mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aquev ous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of water and emulsion-breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

7. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and water-soluble inorganic sulfate and sullite, which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said water-soluble inorganic sulfate and sulite, sodium chloride, at least parts by volume of water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion-breaking liquid which is a glycol containing three to six carbon atoms per molecule, the amounts of said water, said sodium chloride and said emulsion-breaking liquid being suiiicient to produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon oil, water and emulsionbreaking liquid, a hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase and an aqueous phase containing alkali metal green acid sulfonates, water-soluble inorganic sulfate and sulte and a major proportion of said sodium chloride; and separating said three phases from each other.

8. The process as dened in claim 7 in which a watersoluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali met-al mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor 18 proportions of water and emulsion-breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

9. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and water-soluble inorganic sulfate and sulte, which comprises: forming -a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said Water-soluble inorganic sulfate and sulite, at least l0 parts by volume of water per 100 parts by volurne of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hyd-rocarbon oil-soluble emulsion-breaking liquid which is -a glycol containing three to six carbon atoms per molecule, the amounts of said water and said emulsion-breaking liquid being suicient to produce an aqueous phase containing alkali metal green acid sulfonates and water-soluble sulfate and sulte, and a separable hydrocarbon oil-sulfonate phase containing hydrocarbon oil, water, emulsion-breaking liquid and alkali metal mahogany sulfonates; separating said hydrocarbon oil-sulfonate phase from said aqueous phase; mixing with the separated hydrocarbon oil-sulfonate phase an additional amount of a liquid selected from the group consisting of water, and said emulsionbreaking liquid, the amounts of said water and said emulsion-breaking liquid in the resulting mixture being suflicient to produce a concentrated mahogany sulfonate phase containing alkali metal mahogany sulfonates, hydrocarbon oil, water and emulsion breaking liquid and a separable hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase; and separating said hydrocarbon oil phase from said concentrated mahogany sulfonate phase.

l0. The process as defined in claim 9 in which the emulsion-breaking liquid is a dipropylene glycol.

ll. The process as defined in claim 9 in which the emulsion-breaking liquid is propylene glycol.

l2. The process as defined in claim 9 in which the emulsion-breaking liquid, is diethylene glycol.

13. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and water-soluble inorganic sulfate and sulte, which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said water-soluble inorganic sulfate and sullite, sodium chloride, at least l0 parts by volume of Water per 100 parts by Volume of said hydrocarbon oil and sulfonates and at least 5 parts byvolume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion-breaking liquid which is a glycol containing three to six carbon atoms per molecule, the amounts of said water, said sodium chloride and said emulsion-breaking liquid being suicient to produce an aqueous phase containing alkali metal green acid sulfonates, water-soluble sulfate and sulte and said sodium chloride, and a separable hydrocarbon oil-sulfonate phase containing hydrocarbon oil, water, emulsion-breaking liquid and alkali metal mahogany sulfonates; separating said hydrocarbon oil-sulfonate phase from said aqueous phase; mixing with the separated oil-sulfonate phase ann additional amount of a liquid selected from the group consisting of water, and said emulsion-breaking liquid, the amounts of said water, said sodium chloride and said emulsion-breaking liquid in the resulting mixture being suliicient to produce a concentrated mahogany sulfonate phase containing alkali metal mahogany sulfonates, hydrocarbon oil, water and emulsion-breaking liquid and a separable hydrocarbon oil phase rejected from said concentrated mahogany sul- '19 fonate phase; and separating said hydrocarbon oil phase from said concentrated mahogany sulfonate phase.

14. The process as dened in claim 13 in which a watersoluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of water and emulsion-breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

15. The process as defined in claim 13 in which the emulsion-breaking liquid is a dipropylene glycol.

2) 16. The process as denediniclaim' 13 in which the emulsion-breaking liquid is propylene glycol.

17. The process as defined in-claim 13 in which the emulsion-breaking liquid is diethylene glycol.

References Cited in the le of this patent UNITED STATES PATENTS 1,901,383 Voogt Mar. 14, 1933 2,084,506 Rosen June 22, 1937 2,168,315 Blumer Aug. 8, 1939 2,522,212 Dammers Sept. 12, 1950 

1. THE PROCESS OF TREATING A MATERIAL CONSISTING OF A MAJOR PROPORTION OF HYDROCARBON OIL CONTAINING ALKALI METAL MAHOGANY SULFONATES, ALKALI METAL GREEN ACID SULFONATES AND WATER-SOLUBLE INORGANIC SULFATE AND SULFITE, WHICH COMPRISES: FORMING A MIXTURE CONSISTING ESSENTIAL, WHICH COMPRISES: FORMING A MIXTURE CONSISTING ESSENLY OF SAID HDROCARBON OIL, SAID ALKALI METAL MAHOGANY LY OF SAID HYDROCARBON OIL, SAID ALKALI METAL MAHOGANY SULFONATES, SAID ALKALI METAL GREEN ACID SULFONATES, SAID WATER-SOLUBLE INORGANIC SULFATE AND SULFITE. AT LEAST 10 WATER-SOLUBLE INORGANIC SULFATE AND SULFITE, AT LEAST 10 PARTS BY VOLUME OF WATER PER 100 PARTS BY VOLUME OF PARTS BY VOLUME PER 100 PARTS BY VOLUME OF SAID HYDROCARBON SAID HYDROCARBON OIL AND SULFONATES AND AT LEAST 5 PARTS SAID HYDROCARBON OIL AN SULFONATES AND AT LEAST 5 PARTS BY VOLUME PER 100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES OF AHYDROCARBON OIL-SOLUBLE EMULSIONOIL AND SULFONATES OF A HYDROCARBON OIL-SOLUBLE EMULSIONBREAKING LIQUID WHICH IS A GLYCOL CONTAINING THREE TO SIX CARBON ATOMS PER MOLECULE, THE AMOUNTS OF SAID WATER AND SAID EMULSION-BREAKING LIQUID BEING SUFFICIENT TO PROTICLES CARRYING ON THEIR SURFACES A DEPOSIT OF AT LEAST ONE DUCE THREE SEPARABLE PHASES, A CONCENTRATED MAHOGANY SALT OF AN ACID SELECTED FROM THE GOUP CONSISTING OF THE SULFONATE PHASE CONTAINING HYDROCARBON OIL, WATER AND A:A'', B:B'' DISULPHONIC ACIDS OF DINAPHTHYLMETHEMULSION-BREAKING LIQUID, A HYDROCARBON OIL PHASE REANES SAID SALT BEING SOLUBLE IN A SATURATED AQUEOUS SODIUM JECTED FROM SAID CONCENTRATED MAHOGANY SULFONATE PHASE NITRATE SOLUTION AT 20*C. AND AN AQUEOUS PHASE CONTAINING ALKALI METAL GREEN ACID SULFONATES AND WATER-SOLUBLE INORGANIC SULFATE AND SULFITE; AND SEPARATING SAID THREE PHASES FROM EACH OTHER. 